This invention relates to generating embroidery data for controlling stitching out by an embroidery machine.
It is known for an embroidery designer to create an embroidery design on a computer using a design tool. The embroidery design may then be supplied as embroidery data to an embroidery machine (such as a sewing machine) which can then be configured to perform embroidery according to the received embroidery data. Typically, this involves an operator securing a piece of fabric within a hoop (or frame) that the embroidery machine can move relative to its needle, the movement being in accordance with the embroidery data so that the desired embroidery is automatically produced on the fabric. This is known as “stitching out” by the embroidery machine.
Computer implemented tools for designing embroideries typically provide a user interface depicting a fabric (or embroidery workspace) onto which stitches are placed. Stitch placement is performed by indicating a start-point and an end-point of a stitch, although a stitch start-point may be assumed to be the end-point of the immediately preceding stitch. In a mouse operated computer system, indication of stitch start- and end-points can be achieved by clicking one of the mouse buttons. Other input devices can be used in a similar manner.
Despite the capabilities of such embroidery design tools, there are a number of embroidery techniques that can be performed by a human operator of an embroidery machine but that cannot be easily replicated with such design tools. This makes the use of these design tools slow and cumbersome (and sometimes impossible) when designing embroideries based on these embroidery techniques.
One such embroidery technique is the so-called “free motion embroidery” (a description of which is contained in “Free-Motion Machine Embroidery”, Susan Wright, Guide C-213, College of Agriculture and Home Economics, New Mexico State University). In free motion embroidery, the operator of the embroidery machine places the fabric within the hoop and then moves the hoop relative to the needle of the embroidery machine. The operator moves the hoop by hand. For a given needle speed (stitch rate), the faster the operator moves the hoop, the longer a stitch will be.
Current embroidery design tools are not capable of allowing a designer to quickly and easily design an embroidery that has the characteristics of free motion embroidery.